Snap thread gauge



F eb. 28, 1928.

l/V. VEN TOP.'

Patented F eb. 28, 1928.

UNITED STATES `PATENT OFFICE.-

CHARLES e. JOHNSON, oir-marroni), coNNEc'rIcUT.

SNAP THREAD GAUGE.

Application led August 20, 1920, Serial No. 404,791.` lenewelietober 6, 1925.

My invention relates to the class of devices more especially used for gauging threads, for determining cross sectional dimensions, &c.,' and an object of my invention, among others, is to provide a device of this class that shall be simple in construction and particularly effective in operation, and with a minimum depreciation in accuracy `through wear.

-One form of gauge embodying my invention and in the construction and use of which the objects herein set out, as well as others, maybe attained, -is illustrated in the accompanying drawings, in which- .Figure 1 is a face view of my improved gauge.

Figure 2 is an end view of the same, showing its application.

Figure 3 is a viewvin lengthwise sectionthrough one of the branches ofsaid gauge. Figure 4 is a View illustrating the gauge in a little different form.

In the accompanying drawings the numeral 5 indicates the body or stock of my improved gauge that is preferably of U-shape and having branches 6-7 that serve as supports for the `gauging devices. The stock preferably has recesses 8 to receive grips 9 that may be made of rubber or any other suit-able material.

The branches 6--7 have at their ends supporting side parts preferably formed by grooves 10 on the inside edge of each branch, and bearing pins 11-12 for gauging rollers 13 are mounted in the side parts 14 of Said branches, said pins being so arranged that the distance between oppositely disposed rollers ,in the branches may be varied for the purpose of gauging parts of diiferent di-v mensions. v 1

In the form of construction as' herein shown the pins 11 having their ends sup-,-

ported in the branches 6 are eccentric pins. but it will be obvious that all of the pins for supporting the gauging rolls may be of this construction 'if desired. Each end of each pin 11 has a bearing in oneof the side parts 14, the ends Yof each pin constituting its bearing in the side parts being eccentric to the body or main'part that supports a gauging roller. One end of each eccentric pin has a slot 15 by means of which the -pin may be turned, as with ascrew driver, und this end oijeach pin has athreaded opening to receive a retainingscrew 16. The opposite end of each pin has an opening also threaded to receive a clampingscrew 17 that is preferably beveled on the under side of its head, said clamping screws passing through a clamping plate 18 that is held in place as b means of a holding screw 19 extending t rough the plate and into the branch that supports it. Y

In the operatlon `of securing the eccentric 'pins when the proper adjustments thereof msl The rollers 13 are rotatably mounted on the eccentricpins, there being two sets of said rollers, the members of each set of which are .located opposite eachl other in the branches 6 7. These rollers vare provided with annular ribs 21 extendin around their outer suraces, that is, such. ribs extend in the shortest direction around the rollers and are not inclined as is the thread of a screw. This' formation of the ribs lprovides the rollers with corresponding grooves between them allformed in shape and size to correspond with the threads to be measured, and while, in the .structure herein shown. these ribs may correspond in number tothe threads to be measured and are round in form, yet such lesser number and form of ribs on the gauging rollers may be employed as may be desired. It will be noted that the ribs on the rollers of one of the branches are staggered with respect to the ribs of the roller'on the other branch, as shown in Figure 2 of the drawings, altho I do not limit the invention of this precise arrangement, and by the 'term staggered as employed herein, I-mean that a rib on onel roller is located opposite the space between two adjacent ribs on the opposite roller, that is, the crowns of theribs on one roller arenot directly opposite the crowns o f the ribson the opposite roller.

In forming an article to a` certain size it is'common practice at thev present time to allow a certain range within which'the measurements must fall, this range often being somewhat less thanf2/1000th inch in the case of a screw thread, therefore,l I provide two sets of rollers, the 'first' set, that is the set circumferentially novelt first making contact with the piece being measured, being adjusted to the higher limit of the range, and that set further back being adjusted tothe other limit of the range. The article to be gauged will pass through between the first set of rollers but will not pass through the second set of rollers, if'it conforms to the required size. If it will not pass through the first set of rollers it is not small enough, and if it will ass between the secondset f rollers it will too small to satisfy requirements. It will thus be seen that 1by use of the two sets of rollers the required size of a piece of work may be readily determined.

The device as illustrated in Figure 4 is for the purpose of gauging, an article other than avscrew threade one and for this purpose one of the branches of the gauge is provided with an anvil 22 that is fiat on its working surface, which working surface is located opposite the gauging'rollers in the other branch of the gauge, the operation of gauging an article, however, being the same as hereinabove described.

The gauge rollers are of a length a triiie shorter 4than the dlstlnce between thevsitlie parts l a very s 'g t space consequent y existing between the ends of the rollers and side parts, and as shown in the drawings herein, the showing of such space 2O however being necessarily exaggerated as it will be so slight as to be practically impossible of a showing in this way, the difference between the engthof the rollers and the distance between the side parts being approximately 5/1,000th part of an inch. This provision of a sli ht play for the rollers permits them to themselves with respect to the threads on the piece bein gauged and thereby avoid any cramping of t e parts in the lgauging'operation.

Wh' e a considerable portion of the of my invention herein residesin provi 'ng a thread auge having rolls ormed with annular t ead engaging ribs rtherearonnd, it should be clearly understood that the scope of my invention is not limited to this articular construction. Inthe drawmg an` specication- I have particularly illustrated and described my invention'in connection with such a thread gauge (Figs. 1-3) and a gauge for gauging non-threaded arts (Fig. 1.5). In accordance with the reader scope of my invention however it should be understood that the gauge rolls may be 'lain or provided with gauging surfaces o any desiredrconiiguration to per# form the gauging function.`

The gauging members or rollers 13 being round, when the threaded article being gaugedmakes contact with them, this con tact will be with a minimum-.portion of the surface-of bothI said article and the rollers v and'along a line extending crosswise of the thread, thereby providing a line contact between the' rollers and the article being gauged.

`In accordance with the provisions of the patent statutes I have described the principles ofoperation of my invention, together with the device which I now consider to represent the best embodiment thereof; but

I desire to have it understood that the device shown is only` illustrative and that the invention may be carried out-by other means and applied to uses other than those above set out. j

I'claim- 1, A snap auge comprising a stock having opposed ranches, a roller mounted for rotation about its central axis in one of said branches, an opposed gauging member `on the other branch, and means for adjusting the roller bodil in its branch toward and from the other ranch, the said roller being'. free to rotate in the gauging operation.

2. A .snap gauge comprising 'a stock hav.

ing'opposed branches, a roller mounted forv rotation about its central axis in each of the said branches, and means for adjusting one of the rollers bodily in its branch toward and from the other roller, the rollers being free to rotate in the gauging operation. i

3. A limit gauge comprising a stock having opposed branches, a pair of rollers mounted for rotation about their central axes in one of said branches, a pair of opposed gauging rollers rotatably mounted in the other branch, and means for bodily adjusting the Irollersin one branch 'toward and from the rollers in the other branch, the rollers being free to rotate in the gauging operation.

` 4. A gauge comprising a stock having branches, a roller rotatab y mounted in one of said branches and having a central axis and a pluralit of thread engaging surfaces arranged to op osing gaucin otlibr branchfan member located on the means for adjustn the axis of said rolle: in its branch towar and from the other branch. y

5. A gauge vcomprising a stock having branches, al pin Amounted in one of sai branches and having an eccentric portion, al

roller mounted on the eccentric portion of said pin whereby its axis may be moved to-n wardhand fronl the other branch by rotating t e pin an an. opposing auging member located, upon said other ranchofvthe stock. A

, '6. A gauge Acomprising a stock having branches, a pin rotatably mounted in one of said branches, a roller mounted upon the. eccentric portion of said pin and having its periphery formed to engage a thread to be gauged, a clamp plate secured to said branch,f means upon the clamp plate to draw the end of the eccentric pin into contact therewith to t a thread to be gauged, anA

holdl it against movement, and an opposing gauging member located upon the other adjustment between the said ranch of said stock.

7. A thread gauge comprising a stock having opposed branches, a pair of rollers mounted for rotation about their central axes in one of said branches and having a plurality of annular thread engaging suraces arranged to fit 'a thread to be gauged, opposed gauging means on the other branch provided with `xcooperating thread engaging surfaces, and means providing a relative gauging means and the axis of the rollers.

8.'A gauge comprising a stock` havlng Ahaving vopposed branches, a roller mounted for rotation `about its central axis in one of said branches and provided 'with a plurality of annular thread engaging surfaces extending circumferentially about its periphery, an opposed gauging member on the other branch. provided with cooperating thread engaging surfaces, and means providing a relative adjustment between the roller and member toward and fromeach other,

the roller being -free to rotate in the gauging operation.

10. A snap thread gauge comprising a l stock having opposed branches, a roller mounted for rotation about its central 'axis in one of said branches and provided with a plurality -of annular thread engaging surfaces extending circumferentially about its periphery, an opposed gauging member on the "other branch provided with cooperating thread engaging-surfaces, and means for adjusting the roller toward vand from the said member, the lsaid roller being free to rop tate in the gauging operation.

11,'A snap thread gauge comprising a stock having opposed branches, a threadgauging member provided with a plurality of annular thread enga 'ng surfaces extend-- ing circumferentially a out its periphery, a

pin for supporting the roller, means eccentric of the pin and vcooperating therewith to support the roller on one ofthe branches, rotatlon of the said means being adapted to adjust the roller toward and from the otherbranch, andan opposedgauging member on the otherbranch provided -with cooperating thread engaging surfaces.

12. A snap thread auge comprising a stock having opposed ranches, a' pair of opposed rollers mounted at their central axes respectively in the said branches, each of such rollers being provided withl a plurality of annular thread engaging surfaces extending circumferentially about its pe-v riphery and the apexes of the said surfacesl of one roller 'being staggered with respect to those of the opposed roller, and means providing a relative adjustment betweenthe axes of the rollers toward and from each other, the rollers being free to rotate in the gauging operation.

13. A substantially U-shaped limit thread snap gauge comprising a stock having opposed branches, a pairy of rollers mounted for rotation-about their central axes in one of said branches, a pair of opposed gauging rollers mounted for rotation about their-central axes in the other branch, each of the said rollers being provided with a plurality of annular thread engaging surfaces extending circumferentially about its periphery and the apexes of the said surfaces of the rollers in one branch being staggered with' respect to those of the rollers in the other branch, and means for bodily adjusting the rollers of one branch towardl and fromthe rollers of the other branch, the

rollers being free to rotate in the gauging operation.

14.' A thread gauge comprising a stock having branches, a gauging member having its periphery grooved to engage a thread to be gauged, a pin for supportlng the roller, means 'eccentric of the pin and cooperating therewith to support the roller on one of the branches, rotation of the said means being adapted to adjust the roller toward and from lthe other branch, means for securing the first said means against rotatlon, and an oppos-y ing gauging member locatedv in the other branch ofthe stock.

15. A snap thread` gauge comprising av stock having opposed- "branches, aroller mounted forV rotation about its central axis i. in one of said branches, said roller being *provided with a plurality of annular ribs extending circumferentially about its peripher to conform to the thread 'being gauge as to pitch, lead and form, and means ,upon the other branch corresponding to said ribs to receive the thread to e gauged, said means being staggered with respect to lthe ribs on the roller 1n the opposite branch.

16. A snap thread-gauge comprising a stock having opposed branches, a roller mounted for rotation about its central axis in one of said branches, an opposed roller mounted loo for rotation about its central'axis in the l other branch, each of saidrollers being provided with a plurality of annular ribs extending circumferentially about its periphery whlch conform to the thread to be gauged gauging member having beveled thread en' rvgaging ribs extending .around its periphery and having a round central opening within which the pin engages to mount the member thereon, means rotatably mounted in one of the branches and supporting the pin in a relatively eccentric position, the pin and member being adjusted toward and from the other branch vby rotatably adjusting the said means, and an opposed gauging member on the other branch provided with a thread engaging rib or ribs to cooperate with the ribs on the first said member in gauging a thread.

18. A gauge comprising a stock, gaugin members oppositely arranged in the stoc to receive a threaded device to be gan ed between them, one of said members being rotatably mounted in the stock and having a peripheral rib with its entire crown located l in a lane at ri ht angles to the axis of said mem r, wherey devices having threads of of different helix angles may be gaugedby a line contact between said peripheral ri and said threads and means eccentrically supported in said stock and upon which one of said members is rotatably mounted.

19. A auge comprising a stock having opposed Eranches, a gauging roller, a pin on `which the roller is mounted, means rotatably mounted in one of the branches and supportin the pin in a relatively eccentric position, ille pin and roller being adjusted toward and from the other branch by rotatably adjusting-the said means, and an opposing gauging member located on the other rane Y 20. A auge comprising a stock having opposed ranches, a gauging roller,a pin for sup rting the roller, means eccentric of the pin and cooperatin therewith to support the roller on one o the branches, rotation of the said means being adapted to adjust the roller toward and from the other branch, and an opposing .gauging member located on lthesother branch.

' CHARLES G. -JGHNSON 

